1. Field of the Invention
The present invention relates to an oral composition containing polyglycerol fatty acid monoester.
2. Description of the Related Art
Conventional oral compositions generally contain surfactants to increase the cleanability thereof, and the characteristics additionally required for surfactants to be used in oral compositions are an excellent formability, a good overall sensation in mouth (e.g., surfactants must not have unpleasant taste such as bitter taste, astringency, or unpleasant odor), and a high safety factor. Furthermore, a very important characteristic required for surfactants to be used in oral compositions is that the surfactants are suitable for long term storage, in that denaturing (e.g., discoloration and liquid separation) does not occur.
Anionic surfactants and nonionic surfactants are used as a surfactant in conventional oral compositions, and of these surfactants, anionic surfactants such as sodium lauryl sulfate are widely used in oral compositions because of their excellent formability. However, sodium laury sulfate has an inferior juice effect (i.e., the effect not for changing the taste of a juice after using oral compositions) and are disadvantageous in that the stable formulation of, for example, enzymes, therein is difficult. On the other hand, although nonionic surfactants are superior to anionic surfactants in, for example, safety, stabilization of effective components, and juice effect, most nonionic surfactants conventionally used in oral compositions are disadvantageous in that they have a poor foamability, taste, and odor. For example, sucrose laurate (ester) and sucrose myristate (ester) have a relatively good foamability, but have a strong bitter taste. Furthermore, when sucrose fatty acid esters are formulated into dentifrices, the dentifrices are discolored yellow and liquid separation occurs when they are stored for a long term or at an elevated temperature (e.g., at a store in the summer), and thus, are not practical.